over heating

ajracing · #1 (**permalink**) 04-29-2010, 09:43 AM

I need some expert advise. my temp gauge will move from 170, 180 up to 210, back down to 190 and up again. i have replaced the gauge still doing it. i have changed fans, put smaller water pump pulley, still doing it. i was told that because my water outlet from engine to inlet of radiator in lower, that i can't get all the air out of the system. any suggestions,please?

aj:

VintageUpgrades · #2 (**permalink**) 04-29-2010, 09:54 AM

We can check it out if you would like to bring it by. At the very least, I can vacuum fill the cooling system for you.

RICK LAKE · #3 (**permalink**) 04-29-2010, 10:38 AM

ajracing AJ what thermostat is in the motor?? Are you just straight driving or racing? Did this just start happening or has this been going on for a while? I do agree about vacuum of the coolant system to see if any air bubbles are caught in the system. The other thing is to install a small bleeder valve where you are talking about. This will also let out the air if you don't have a vacuum pump. Not seeing your pulleys you may have gone in the wrong direction for size on all pulleys. The stock ones with an A/C water pump should more than keep the motor from running hot. If you run under drive pulleys this is also causing a heating problem. Rick L.

ajracing · #4 (**permalink**) 04-29-2010, 10:43 AM

thanks,
i'm running a 180 deg. therm.. i just got the car so, i can't tell how long.by the way head gaskets are fine.

wetdog · #5 (**permalink**) 04-29-2010, 11:11 AM

AJ, you have air in the system I went through hell trying to eliminate it ..finally jacked up car nose high and filled it while squuezing lower hose to remove bubbles . A thermostat with a small hole 3/32 to 1/8 " mounted at 12 oclock helps too good luck WD

ajracing · #6 (**permalink**) 04-29-2010, 11:23 AM

you mean the hole in the therms. should be at 12 o'clock?

bmeyer29 · #7 (**permalink**) 05-02-2010, 09:02 PM

I had erratic temp problems when I first got my cobra. Take a look at this thread; you may see parallels to what you are seeing with your engine.

http://clubcobra.com/forums/showthread.php?t=90618

ajracing · #8 (**permalink**) 05-03-2010, 11:04 AM

Bob,

You have given me hope to my problem. I have tried vaccuming the air out, still have the problem. next i am going to try the incline method and then may have to install tank. Not that I would wish this on anyone, but I'm glade to see I'm not the only one. Keep all that have wrote Posted.

AJ

Dwight · #9 (**permalink**) 05-03-2010, 03:52 PM

What ratio of water and anti-freeze are you running? 50/50 max. We run about 25% anti-freeze.

If you have a heat sensor located in the top - front of your intake, you can open it untill water runs out and then re-tighten the sensor.
It's a high point in the water system.

Dwight

Dwight · #10 (**permalink**) 05-03-2010, 04:00 PM

this is a pic of a 351W but I think the 289 is the same location. The sensor is located just in front of the number 5 runner. Behind the plug wire.

Dwight

ajracing · #11 (**permalink**) 05-03-2010, 04:27 PM

thanks, at this piont I'll try any and everything. Hard to just stand there and look at the car in the garage.

AJ

ajracing · #12 (**permalink**) 05-03-2010, 04:34 PM

my temp gauge is mech. not elec.

twobjshelbys · #13 (**permalink**) 05-04-2010, 05:14 PM

I had the same problem - very erratic temp swings over very short intervals.

At first I thought air bubble too. I got one of the Kirkham tanks which successfully raised the fill point to the high point of the system. It still happened.

Eventually we'd tried everything, including thermostats and various caps, and the problem ended up being the water pump itself - the pulley and everything were turning but the impeller itself was broken and not spinning - the impeller shaft connection had broken loose and was just spinning. The blades could line up to a dead spot where no water would flow then it would take a little shift which would then flow a little while.

This was after everyone assured me that if the pump would spin that all was well.

cman46 · #14 (**permalink**) 05-05-2010, 07:25 AM

The problem is called Cavitation. Most Cobra and Street Rod radiators do not have expansion tanks. With the typical cap designed for overflow recovery no expansion tank means water out, air in. I do not choose to debate all the types of recovery tanks so let's just keep it simple. Coolant out when hot feeding the bottom of a tank of some sort. The tank should be even with or a tick higher than the filler cap entry. That way coolant in from the bottom and as it cools, flow is assured and no air. Engineering is up to the owner. That is my story and I am sticking to it. Colin

ajracing · #15 (**permalink**) 05-05-2010, 10:06 AM

At this point I'll try every option.